Morgan Olsson wrote:
>
> I think we can learn sometning from why the electric fence unit broke. (my recent post "Urgent ST FJ0916CI datasheet"):
>
> The IC supply radial cased electrilytic cap has become loose because the rubber gasket had expanded and pulled the solder joint broken.  I guess then the PWM got crazy and destroyed the power FET.  The tracks of that is the IC, Power FET, and a resistor got blown.
>
> The original failure reason i tink is that the cirquit board is covered with some grease, and it seems something in the grease diffuses into the gasket which then expands.
>
> I have also found another radial eletrolytic cap on the cirquit board hich has also pushed itself out.


I think it may be heat related. If you have two
electro caps bulged open or exploded open, that is
probably the source of the "greasy" stuff.
The greasy stuff my be corrosive and poisonous. :o)

Am I right in thinking this electric fence unit has
been working non-stop in the summer sun? Might just
be that the heat finally got to the 12 year old caps
and they blew their guts.
-Roman

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